[linux-block.git] / include / net / mptcp.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Multipath TCP
 *
 * Copyright (c) 2017 - 2019, Intel Corporation.
 */

#ifndef __NET_MPTCP_H
#define __NET_MPTCP_H

#include <linux/skbuff.h>
#include <linux/tcp.h>
#include <linux/types.h>

struct mptcp_info;
struct mptcp_sock;
struct seq_file;

/* MPTCP sk_buff extension data */
struct mptcp_ext {
	union {
		u64	data_ack;
		u32	data_ack32;
	};
	u64		data_seq;
	u32		subflow_seq;
	u16		data_len;
	__sum16		csum;
	u8		use_map:1,
			dsn64:1,
			data_fin:1,
			use_ack:1,
			ack64:1,
			mpc_map:1,
			frozen:1,
			reset_transient:1;
	u8		reset_reason:4,
			csum_reqd:1,
			infinite_map:1;
};

#define MPTCPOPT_HMAC_LEN	20
#define MPTCP_RM_IDS_MAX	8

struct mptcp_rm_list {
	u8 ids[MPTCP_RM_IDS_MAX];
	u8 nr;
};

struct mptcp_addr_info {
	u8			id;
	sa_family_t		family;
	__be16			port;
	union {
		struct in_addr	addr;
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
		struct in6_addr	addr6;
#endif
	};
};

struct mptcp_out_options {
#if IS_ENABLED(CONFIG_MPTCP)
	u16 suboptions;
	struct mptcp_rm_list rm_list;
	u8 join_id;
	u8 backup;
	u8 reset_reason:4,
	   reset_transient:1,
	   csum_reqd:1,
	   allow_join_id0:1;
	union {
		struct {
			u64 sndr_key;
			u64 rcvr_key;
			u64 data_seq;
			u32 subflow_seq;
			u16 data_len;
			__sum16 csum;
		};
		struct {
			struct mptcp_addr_info addr;
			u64 ahmac;
		};
		struct {
			struct mptcp_ext ext_copy;
			u64 fail_seq;
		};
		struct {
			u32 nonce;
			u32 token;
			u64 thmac;
			u8 hmac[MPTCPOPT_HMAC_LEN];
		};
	};
#endif
};

#ifdef CONFIG_MPTCP
void mptcp_init(void);

static inline bool sk_is_mptcp(const struct sock *sk)
{
	return tcp_sk(sk)->is_mptcp;
}

static inline bool rsk_is_mptcp(const struct request_sock *req)
{
	return tcp_rsk(req)->is_mptcp;
}

static inline bool rsk_drop_req(const struct request_sock *req)
{
	return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
}

void mptcp_space(const struct sock *ssk, int *space, int *full_space);
bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
		       unsigned int *size, struct mptcp_out_options *opts);
bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
			  struct mptcp_out_options *opts);
bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
			       unsigned int *size, unsigned int remaining,
			       struct mptcp_out_options *opts);
bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb);

void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp,
			 struct mptcp_out_options *opts);

void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info);

/* move the skb extension owership, with the assumption that 'to' is
 * newly allocated
 */
static inline void mptcp_skb_ext_move(struct sk_buff *to,
				      struct sk_buff *from)
{
	if (!skb_ext_exist(from, SKB_EXT_MPTCP))
		return;

	if (WARN_ON_ONCE(to->active_extensions))
		skb_ext_put(to);

	to->active_extensions = from->active_extensions;
	to->extensions = from->extensions;
	from->active_extensions = 0;
}

static inline void mptcp_skb_ext_copy(struct sk_buff *to,
				      struct sk_buff *from)
{
	struct mptcp_ext *from_ext;

	from_ext = skb_ext_find(from, SKB_EXT_MPTCP);
	if (!from_ext)
		return;

	from_ext->frozen = 1;
	skb_ext_copy(to, from);
}

static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
				     const struct mptcp_ext *from_ext)
{
	/* MPTCP always clears the ext when adding it to the skb, so
	 * holes do not bother us here
	 */
	return !from_ext ||
	       (to_ext && from_ext &&
	        !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
}

/* check if skbs can be collapsed.
 * MPTCP collapse is allowed if neither @to or @from carry an mptcp data
 * mapping, or if the extension of @to is the same as @from.
 * Collapsing is not possible if @to lacks an extension, but @from carries one.
 */
static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
					  const struct sk_buff *from)
{
	return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
				 skb_ext_find(from, SKB_EXT_MPTCP));
}

void mptcp_seq_show(struct seq_file *seq);
int mptcp_subflow_init_cookie_req(struct request_sock *req,
				  const struct sock *sk_listener,
				  struct sk_buff *skb);
struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
					       struct sock *sk_listener,
					       bool attach_listener);

__be32 mptcp_get_reset_option(const struct sk_buff *skb);

static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
{
	if (skb_ext_exist(skb, SKB_EXT_MPTCP))
		return mptcp_get_reset_option(skb);

	return htonl(0u);
}
#else

static inline void mptcp_init(void)
{
}

static inline bool sk_is_mptcp(const struct sock *sk)
{
	return false;
}

static inline bool rsk_is_mptcp(const struct request_sock *req)
{
	return false;
}

static inline bool rsk_drop_req(const struct request_sock *req)
{
	return false;
}

static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
				     unsigned int *size,
				     struct mptcp_out_options *opts)
{
	return false;
}

static inline bool mptcp_synack_options(const struct request_sock *req,
					unsigned int *size,
					struct mptcp_out_options *opts)
{
	return false;
}

static inline bool mptcp_established_options(struct sock *sk,
					     struct sk_buff *skb,
					     unsigned int *size,
					     unsigned int remaining,
					     struct mptcp_out_options *opts)
{
	return false;
}

static inline bool mptcp_incoming_options(struct sock *sk,
					  struct sk_buff *skb)
{
	return true;
}

static inline void mptcp_skb_ext_move(struct sk_buff *to,
				      const struct sk_buff *from)
{
}

static inline void mptcp_skb_ext_copy(struct sk_buff *to,
				      struct sk_buff *from)
{
}

static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
					  const struct sk_buff *from)
{
	return true;
}

static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { }
static inline void mptcp_seq_show(struct seq_file *seq) { }

static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
						const struct sock *sk_listener,
						struct sk_buff *skb)
{
	return 0; /* TCP fallback */
}

static inline struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
							     struct sock *sk_listener,
							     bool attach_listener)
{
	return NULL;
}

static inline __be32 mptcp_reset_option(const struct sk_buff *skb)  { return htonl(0u); }
#endif /* CONFIG_MPTCP */

#if IS_ENABLED(CONFIG_MPTCP_IPV6)
int mptcpv6_init(void);
void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
#elif IS_ENABLED(CONFIG_IPV6)
static inline int mptcpv6_init(void) { return 0; }
static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
#endif

#if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL)
struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk);
#else
static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; }
#endif

#if !IS_ENABLED(CONFIG_MPTCP)
struct mptcp_sock { };
#endif

#endif /* __NET_MPTCP_H */
Commit	Line	Data
3ee17bc7 MM	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	/*
	3	* Multipath TCP
	4	*
	5	* Copyright (c) 2017 - 2019, Intel Corporation.
	6	*/
	7
	8	#ifndef __NET_MPTCP_H
	9	#define __NET_MPTCP_H
	10
85712484	11	#include <linux/skbuff.h>
eda7acdd	12	#include <linux/tcp.h>
3ee17bc7 MM	13	#include <linux/types.h>
3ee17bc7 MM	14
61bc6e82 FW	15	struct mptcp_info;
61bc6e82 FW	16	struct mptcp_sock;
fc518953 FW	17	struct seq_file;
fc518953 FW	18
3ee17bc7 MM	19	/* MPTCP sk_buff extension data */
3ee17bc7 MM	20	struct mptcp_ext {
a0c1d0ea CP	21	union {
	22	u64 data_ack;
	23	u32 data_ack32;
	24	};
3ee17bc7 MM	25	u64 data_seq;
	26	u32 subflow_seq;
	27	u16 data_len;
d0cc2987	28	__sum16 csum;
3ee17bc7 MM	29	u8 use_map:1,
	30	dsn64:1,
	31	data_fin:1,
	32	use_ack:1,
	33	ack64:1,
cc7972ea	34	mpc_map:1,
5a369ca6	35	frozen:1,
dc87efdb	36	reset_transient:1;
208e8f66	37	u8 reset_reason:4,
1e39e5a3 GT	38	csum_reqd:1,
1e39e5a3 GT	39	infinite_map:1;
3ee17bc7 MM	40	};
3ee17bc7 MM	41
f7657ff4	42	#define MPTCPOPT_HMAC_LEN 20
6445e17a GT	43	#define MPTCP_RM_IDS_MAX 8
	44
	45	struct mptcp_rm_list {
	46	u8 ids[MPTCP_RM_IDS_MAX];
	47	u8 nr;
	48	};
	49
30f60bae GT	50	struct mptcp_addr_info {
	51	u8 id;
	52	sa_family_t family;
	53	__be16 port;
	54	union {
	55	struct in_addr addr;
	56	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
	57	struct in6_addr addr6;
	58	#endif
	59	};
	60	};
	61
eda7acdd PK	62	struct mptcp_out_options {
	63	#if IS_ENABLED(CONFIG_MPTCP)
	64	u16 suboptions;
6445e17a	65	struct mptcp_rm_list rm_list;
f296234c PK	66	u8 join_id;
f296234c PK	67	u8 backup;
06fe1719 GT	68	u8 reset_reason:4,
06fe1719 GT	69	reset_transient:1,
bab6b88e GT	70	csum_reqd:1,
bab6b88e GT	71	allow_join_id0:1;
d7b26908 PA	72	union {
	73	struct {
	74	u64 sndr_key;
	75	u64 rcvr_key;
f7cc8890 DC	76	u64 data_seq;
	77	u32 subflow_seq;
	78	u16 data_len;
	79	__sum16 csum;
d7b26908 PA	80	};
	81	struct {
	82	struct mptcp_addr_info addr;
	83	u64 ahmac;
	84	};
c25aeb4e GT	85	struct {
	86	struct mptcp_ext ext_copy;
	87	u64 fail_seq;
	88	};
d7b26908 PA	89	struct {
	90	u32 nonce;
	91	u32 token;
	92	u64 thmac;
f7657ff4	93	u8 hmac[MPTCPOPT_HMAC_LEN];
d7b26908 PA	94	};
d7b26908 PA	95	};
eda7acdd PK	96	#endif
	97	};
	98
85712484	99	#ifdef CONFIG_MPTCP
f870fa0b MM	100	void mptcp_init(void);
f870fa0b MM	101
cec37a6e PK	102	static inline bool sk_is_mptcp(const struct sock *sk)
	103	{
	104	return tcp_sk(sk)->is_mptcp;
	105	}
	106
	107	static inline bool rsk_is_mptcp(const struct request_sock *req)
	108	{
	109	return tcp_rsk(req)->is_mptcp;
	110	}
	111
90bf4513 PA	112	static inline bool rsk_drop_req(const struct request_sock *req)
	113	{
	114	return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
	115	}
	116
071c8ed6	117	void mptcp_space(const struct sock ssk, int space, int *full_space);
cc7972ea CP	118	bool mptcp_syn_options(struct sock sk, const struct sk_buff skb,
cc7972ea CP	119	unsigned int size, struct mptcp_out_options opts);
cec37a6e PK	120	bool mptcp_synack_options(const struct request_sock req, unsigned int size,
	121	struct mptcp_out_options *opts);
	122	bool mptcp_established_options(struct sock sk, struct sk_buff skb,
	123	unsigned int *size, unsigned int remaining,
	124	struct mptcp_out_options *opts);
6787b7e3	125	bool mptcp_incoming_options(struct sock sk, struct sk_buff skb);
cec37a6e	126
ea66758c	127	void mptcp_write_options(struct tcphdr th, __be32 ptr, struct tcp_sock *tp,
fa3fe2b1	128	struct mptcp_out_options *opts);
eda7acdd	129
61bc6e82 FW	130	void mptcp_diag_fill_info(struct mptcp_sock msk, struct mptcp_info info);
61bc6e82 FW	131
85712484 MM	132	/* move the skb extension owership, with the assumption that 'to' is
	133	* newly allocated
	134	*/
	135	static inline void mptcp_skb_ext_move(struct sk_buff *to,
	136	struct sk_buff *from)
	137	{
	138	if (!skb_ext_exist(from, SKB_EXT_MPTCP))
	139	return;
	140
	141	if (WARN_ON_ONCE(to->active_extensions))
	142	skb_ext_put(to);
	143
	144	to->active_extensions = from->active_extensions;
	145	to->extensions = from->extensions;
	146	from->active_extensions = 0;
	147	}
	148
5a369ca6 PA	149	static inline void mptcp_skb_ext_copy(struct sk_buff *to,
	150	struct sk_buff *from)
	151	{
	152	struct mptcp_ext *from_ext;
	153
	154	from_ext = skb_ext_find(from, SKB_EXT_MPTCP);
	155	if (!from_ext)
	156	return;
	157
	158	from_ext->frozen = 1;
	159	skb_ext_copy(to, from);
	160	}
	161
85712484 MM	162	static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
	163	const struct mptcp_ext *from_ext)
	164	{
	165	/* MPTCP always clears the ext when adding it to the skb, so
	166	* holes do not bother us here
	167	*/
	168	return !from_ext \|\|
	169	(to_ext && from_ext &&
	170	!memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
	171	}
	172
	173	/* check if skbs can be collapsed.
	174	* MPTCP collapse is allowed if neither @to or @from carry an mptcp data
	175	* mapping, or if the extension of @to is the same as @from.
	176	* Collapsing is not possible if @to lacks an extension, but @from carries one.
	177	*/
	178	static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
	179	const struct sk_buff *from)
	180	{
	181	return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
	182	skb_ext_find(from, SKB_EXT_MPTCP));
	183	}
	184
fc518953	185	void mptcp_seq_show(struct seq_file *seq);
c83a47e5 FW	186	int mptcp_subflow_init_cookie_req(struct request_sock *req,
	187	const struct sock *sk_listener,
	188	struct sk_buff *skb);
3fff8818 MB	189	struct request_sock mptcp_subflow_reqsk_alloc(const struct request_sock_ops ops,
	190	struct sock *sk_listener,
	191	bool attach_listener);
dc87efdb FW	192
	193	__be32 mptcp_get_reset_option(const struct sk_buff *skb);
	194
	195	static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
	196	{
	197	if (skb_ext_exist(skb, SKB_EXT_MPTCP))
	198	return mptcp_get_reset_option(skb);
	199
	200	return htonl(0u);
	201	}
85712484 MM	202	#else
85712484 MM	203
f870fa0b MM	204	static inline void mptcp_init(void)
	205	{
	206	}
	207
cec37a6e PK	208	static inline bool sk_is_mptcp(const struct sock *sk)
	209	{
	210	return false;
	211	}
	212
	213	static inline bool rsk_is_mptcp(const struct request_sock *req)
	214	{
	215	return false;
	216	}
	217
90bf4513 PA	218	static inline bool rsk_drop_req(const struct request_sock *req)
	219	{
	220	return false;
	221	}
	222
cc7972ea CP	223	static inline bool mptcp_syn_options(struct sock sk, const struct sk_buff skb,
cc7972ea CP	224	unsigned int *size,
cec37a6e PK	225	struct mptcp_out_options *opts)
	226	{
	227	return false;
	228	}
	229
cec37a6e PK	230	static inline bool mptcp_synack_options(const struct request_sock *req,
	231	unsigned int *size,
	232	struct mptcp_out_options *opts)
	233	{
	234	return false;
	235	}
	236
	237	static inline bool mptcp_established_options(struct sock *sk,
	238	struct sk_buff *skb,
	239	unsigned int *size,
	240	unsigned int remaining,
	241	struct mptcp_out_options *opts)
	242	{
	243	return false;
	244	}
	245
6787b7e3	246	static inline bool mptcp_incoming_options(struct sock *sk,
77d0cab9	247	struct sk_buff *skb)
648ef4b8	248	{
6787b7e3	249	return true;
648ef4b8 MM	250	}
648ef4b8 MM	251
85712484 MM	252	static inline void mptcp_skb_ext_move(struct sk_buff *to,
	253	const struct sk_buff *from)
	254	{
	255	}
	256
5a369ca6 PA	257	static inline void mptcp_skb_ext_copy(struct sk_buff *to,
	258	struct sk_buff *from)
	259	{
	260	}
	261
85712484 MM	262	static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
	263	const struct sk_buff *from)
	264	{
	265	return true;
	266	}
	267
071c8ed6	268	static inline void mptcp_space(const struct sock ssk, int s, int *fs) { }
fc518953	269	static inline void mptcp_seq_show(struct seq_file *seq) { }
c83a47e5 FW	270
	271	static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
	272	const struct sock *sk_listener,
	273	struct sk_buff *skb)
	274	{
	275	return 0; /* TCP fallback */
	276	}
dc87efdb	277
3fff8818 MB	278	static inline struct request_sock mptcp_subflow_reqsk_alloc(const struct request_sock_ops ops,
	279	struct sock *sk_listener,
	280	bool attach_listener)
	281	{
	282	return NULL;
	283	}
	284
dc87efdb	285	static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); }
85712484	286	#endif /* CONFIG_MPTCP */
f870fa0b MM	287
	288	#if IS_ENABLED(CONFIG_MPTCP_IPV6)
	289	int mptcpv6_init(void);
31484d56	290	void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
f870fa0b	291	#elif IS_ENABLED(CONFIG_IPV6)
31484d56 GU	292	static inline int mptcpv6_init(void) { return 0; }
31484d56 GU	293	static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
f870fa0b MM	294	#endif
f870fa0b MM	295
3bc253c2 GT	296	#if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL)
	297	struct mptcp_sock bpf_mptcp_sock_from_subflow(struct sock sk);
	298	#else
	299	static inline struct mptcp_sock bpf_mptcp_sock_from_subflow(struct sock sk) { return NULL; }
	300	#endif
	301
f1d41f77 JO	302	#if !IS_ENABLED(CONFIG_MPTCP)
	303	struct mptcp_sock { };
	304	#endif
	305
3ee17bc7	306	#endif /* __NET_MPTCP_H */